The term phonation has slightly different meanings depending on the subfield of phonetics. Among some phoneticians, phonation is the process by which the vocal folds produce certain sounds through quasi-periodic vibration. This is the definition used among those who study laryngeal anatomy and physiology and speech production in general. Phoneticians in other subfields, such as linguistic phonetics, call this process voicing, and use the term phonation to refer to any oscillatory state of any part of the larynx that modifies the airstream, of which voicing is just one example. Voiceless and supra-glottal phonations are included under this definition.
The phonatory process, or voicing, occurs when air is expelled from the lungs through the glottis, creating a pressure drop across the larynx. When this drop becomes sufficiently large, the vocal folds start to oscillate. The minimum pressure drop required to achieve phonation is called the phonation threshold pressure (PTP),[1][2] and for humans with normal vocal folds, it is approximately 2–3cm H2O. The motion of the vocal folds during oscillation is mostly lateral, though there is also some superior component as well. However, there is almost no motion along the length of the vocal folds. The oscillation of the vocal folds serves to modulate the pressure and flow of the air through the larynx, and this modulated airflow is the main component of the sound of most voicedphones.
The sound that the larynx produces is a harmonic series. In other words, it consists of a fundamental tone (called the fundamental frequency, the main acoustic cue for the percept pitch) accompanied by harmonic overtones, which are multiples of the fundamental frequency.[3] According to the source–filter theory, the resulting sound excites the resonance chamber that is the vocal tract to produce the individual speech sounds.
The vocal folds will not oscillate if they are not sufficiently close to one another, are not under sufficient tension or under too much tension, or if the pressure drop across the larynx is not sufficiently large.[4] In linguistics, a phone is called voiceless if there is no phonation during its occurrence.[5] In speech, voiceless phones are associated with vocal folds that are elongated, highly tensed, and placed laterally (abducted) when compared to vocal folds during phonation.[6]
Fundamental frequency, the main acoustic cue for the percept pitch, can be varied through a variety of means. Large scale changes are accomplished by increasing the tension in the vocal folds through contraction of the cricothyroid muscle. Smaller changes in tension can be effected by contraction of the thyroarytenoid muscle or changes in the relative position of the thyroid and cricoid cartilages, as may occur when the larynx is lowered or raised, either volitionally or through movement of the tongue to which the larynx is attached via the hyoid bone.[6] In addition to tension changes, fundamental frequency is also affected by the pressure drop across the larynx, which is mostly affected by the pressure in the lungs, and will also vary with the distance between the vocal folds. Variation in fundamental frequency is used linguistically to produce intonation and tone.
There are currently two main theories as to how vibration of the vocal folds is initiated: the myoelastic theory and the aerodynamic theory.[7] These two theories are not in contention with one another and it is quite possible that both theories are true and operating simultaneously to initiate and maintain vibration. A third theory, the neurochronaxic theory, was in considerable vogue in the 1950s, but has since been largely discredited.
Myoelastic and aerodynamic theory
The myoelastic theory states that when the vocal cords are brought together and breath pressure is applied to them, the cords remain closed until the pressure beneath them, the subglottic pressure, is sufficient to push them apart, allowing air to escape and reducing the pressure enough for the muscle tension recoil to pull the folds back together again. The pressure builds up once again until the cords are pushed apart, and the whole cycle keeps repeating itself. The rate at which the cords open and close, the number of cycles per second, determines the pitch of the phonation.[8]
The aerodynamic theory is based on the Bernoulli energy law in fluids. The theory states that when a stream of breath is flowing through the glottis while the arytenoid cartilages are held together (by the action of the interarytenoid muscles), a push-pull effect is created on the vocal fold tissues that maintains self-sustained oscillation. The push occurs during glottal opening, when the glottis is convergent, and the pull occurs during glottal closing, when the glottis is divergent.[1] Such an effect causes a transfer of energy from the airflow to the vocal fold tissues which overcomes losses by dissipation and sustain the oscillation.[2] The amount of lung pressure needed to begin phonation is defined by Titze as the oscillation threshold pressure.[1] During glottal closure, the air flow is cut off until breath pressure pushes the folds apart and the flow starts up again, causing the cycles to repeat.[8] The textbook entitled Myoelastic Aerodynamic Theory of Phonation[7] by Ingo Titze credits Janwillem van den Berg as the originator of the theory and provides detailed mathematical development of the theory.
Neurochronaxic theory
This theory states that the frequency of the vocal fold vibration is determined by the chronaxie of the recurrent nerve, and not by breath pressure or muscular tension. Advocates of this theory thought that every single vibration of the vocal folds was due to an impulse from the recurrent laryngeal nerves and that the acoustic center in the brain regulated the speed of vocal fold vibration.[8] Speech and voice scientists have long since abandoned this theory as the muscles have been shown to not be able to contract fast enough to accomplish the vibration. In addition, persons with paralyzed vocal folds can produce phonation, which would not be possible according to this theory. Phonation occurring in excised larynges would also not be possible according to this theory.
State of the glottis
Vocal folds when spread
Vocal folds when phonating
Different glottis positions: A. Glottis closure; B. phonation position; C. whisper position; D. breath position; E. respiratory position or resting position; F. deep breathing position
In linguistic phonetic treatments of phonation, such as those of Peter Ladefoged, phonation was considered to be a matter of points on a continuum of tension and closure of the vocal cords. More intricate mechanisms were occasionally described, but they were difficult to investigate, and until recently the state of the glottis and phonation were considered to be nearly synonymous.[9][pageneeded]
Having greater airflow than in modal voice before or after a stricture; arytenoid cartilages may be further apart than in voiceless
Breathy voice
Vocal cords vibrating but without appreciable contact; arytenoid cartilages further apart than in modal voice
Slack voice
Vocal cords vibrating but more loosely than in modal voice
Creaky voice
Vocal cords vibrating anteriorly, but with the arytenoid cartilages pressed together; lower airflow than in modal voice
Stiff voice
Vocal cords vibrating but more stiffly than in modal voice
If the vocal cords are completely relaxed, with the arytenoid cartilages apart for maximum airflow, the cords do not vibrate. This is voiceless phonation, and is extremely common with obstruents. If the arytenoids are pressed together for glottal closure, the vocal cords block the airstream, producing stop sounds such as the glottal stop. In between there is a sweet spot of maximum vibration. Also, the existence of an optimal glottal shape for ease of phonation has been shown, at which the lung pressure required to initiate the vocal cord vibration is minimum.[4] This is modal voice, and is the normal state for vowels and sonorants in all the world's languages. However, the aperture of the arytenoid cartilages, and therefore the tension in the vocal cords, is one of degree between the end points of open and closed, and there are several intermediate situations utilized by various languages to make contrasting sounds.[9][pageneeded]
For example, Gujarati has vowels with a partially lax phonation called breathy voice or murmured voice (transcribed in IPA with a subscript umlaut ◌̤), while Burmese has vowels with a partially tense phonation called creaky voice or laryngealized voice (transcribed in IPA with a subscript tilde ◌̰). The Jalapa dialect of Mazatec is unusual in contrasting both with modal voice in a three-way distinction. (Mazatec is a tonal language, so the glottis is making several tonal distinctions simultaneously with the phonation distinctions.)[9][pageneeded]
Mazatec
breathy voice
[ja̤]
he wears
modal voice
[já]
tree
creaky voice
[ja̰]
he carries
Note: There was an editing error in the source of this information. The latter two translations may have been mixed up.
Javanese does not have modal voice in its stops, but contrasts two other points along the phonation scale, with more moderate departures from modal voice, called slack voice and stiff voice. The "muddy" consonants in Shanghainese are slack voice; they contrast with tenuis and aspirated consonants.[9][pageneeded]
Although each language may be somewhat different, it is convenient to classify these degrees of phonation into discrete categories. A series of seven alveolar stops, with phonations ranging from an open/lax to a closed/tense glottis, are:
The IPA diacritics under-ring and subscript wedge, commonly called "voiceless" and "voiced", are sometimes added to the symbol for a voiced sound to indicate more lax/open (slack) and tense/closed (stiff) states of the glottis, respectively. (Ironically, adding the 'voicing' diacritic to the symbol for a voiced consonant indicates less modal voicing, not more, because a modally voiced sound is already fully voiced, at its sweet spot, and any further tension in the vocal cords dampens their vibration.)[9][pageneeded]
Alsatian, like several Germanic languages, has a typologically unusual phonation in its stops. The consonants transcribed /b̥/,/d̥/,/ɡ̊/ (ambiguously called "lenis") are partially voiced: The vocal cords are positioned as for voicing, but do not actually vibrate. That is, they are technically voiceless, but without the open glottis usually associated with voiceless stops. They contrast with both modally voiced /b,d,ɡ/ and modally voiceless /p,t,k/ in French borrowings, as well as aspirated /kʰ/ word initially.[9][pageneeded]
If the arytenoid cartiledges are parted to admit turbulent airflow, the result is whisper phonation if the vocal folds are adducted, and whispery voice phonation (murmur) if the vocal folds vibrate modally. Whisper phonation is heard in many productions of French oui!, and the "voiceless" vowels of many North American languages are actually whispered.[10]
Glottal consonants
It has long been noted that in many languages, both phonologically and historically, the glottal consonants[ʔ,ɦ,h] do not behave like other consonants. Phonetically, they have no manner or place of articulation other than the state of the glottis: glottal closure for [ʔ], breathy voice for [ɦ], and open airstream for [h]. Some phoneticians have described these sounds as neither glottal nor consonantal, but instead as instances of pure phonation, at least in many European languages. However, in Semitic languages they do appear to be true glottal consonants.[9][pageneeded]
Supra-glottal phonation
In the last few decades it has become apparent that phonation may involve the entire larynx, with as many as six valves and muscles working either independently or together. From the glottis upward, these articulations are:[11]
glottal (the vocal cords), producing the distinctions described above
ventricular (the 'false vocal cords', partially covering and damping the glottis)
Until the development of fiber-opticlaryngoscopy, the full involvement of the larynx during speech production was not observable, and the interactions among the six laryngeal articulators is still poorly understood. However, at least two supra-glottal phonations appear to be widespread in the world's languages. These are harsh voice ('ventricular' or 'pressed' voice), which involves overall constriction of the larynx, and faucalized voice ('hollow' or 'yawny' voice), which involves overall expansion of the larynx.[11]
The Bor dialect of Dinka has contrastive modal, breathy, faucalized, and harsh voice in its vowels, as well as three tones. The ad hoc diacritics employed in the literature are a subscript double quotation mark for faucalized voice, [a͈], and underlining for harsh voice, [a̠].[11] Examples are,
Voice
modal
breathy
harsh
faucalized
Bor Dinka
tɕìt
tɕì̤t
tɕì̠t
tɕì͈t
diarrhea
go ahead
scorpions
to swallow
Other languages with these contrasts are Bai (modal, breathy, and harsh voice), Kabiye (faucalized and harsh voice, previously seen as ±ATR), Somali (breathy and harsh voice).[11]
In languages such as French and Portuguese, all obstruents occur in pairs, one modally voiced and one voiceless: [b] [d] [g] [v] [z] [ʒ] → [p] [t] [k] [f] [s] [ʃ].
In English, every voiced fricative corresponds to a voiceless one. For the pairs of English stops, however, the distinction is better specified as voice onset time rather than simply voice: In initial position, /b d g/ are only partially voiced (voicing begins during the hold of the consonant), and /p t k/ are aspirated (voicing begins only well after its release). Certain English morphemes have voiced and voiceless allomorphs, such as: the plural, verbal, and possessive endings spelled -s (voiced in kids/kɪdz/ but voiceless in kits/kɪts/), and the past-tense ending spelled -ed (voiced in buzzed/bʌzd/ but voiceless in fished/fɪʃt/).
A few European languages, such as Finnish, have no phonemically voiced obstruents but pairs of long and short consonants instead. Outside Europe, the lack of voicing distinctions is common; indeed, in Australian languages it is nearly universal. In languages without the distinction between voiceless and voiced obstruents, they are realized as voiced in voiced environments, such as between vowels, and voiceless elsewhere.
In phonology, a register is a combination of tone and vowel phonation into a single phonological parameter. For example, among its vowels, Burmese combines modal voice with low tone, breathy voice with falling tone, creaky voice with high tone, and glottal closure with high tone. These four registers contrast with each other, but no other combination of phonation (modal, breath, creak, closed) and tone (high, low, falling) is found.
Among vocal pedagogues and speech pathologists, a vocal register also refers to a particular phonation limited to a particular range of pitch, which possesses a characteristic sound quality.[12] The term "register" may be used for several distinct aspects of the human voice:[8]
A particular part of the vocal range, such as the upper, middle, or lower registers, which may be bounded by vocal breaks
Breathy voice is a phonation in which the vocal folds vibrate, as they do in normal (modal) voicing, but are adjusted to let more air escape which produces a sighing-like sound. A simple breathy phonation,, can sometimes be heard as an allophone of English between vowels, such as in the word behind, for some speakers.
The glottis is the opening between the vocal folds. The glottis is crucial in producing sound from the vocal folds.
Phonetics is a branch of linguistics that studies how humans produce and perceive sounds, or in the case of sign languages, the equivalent aspects of sign. Linguists who specialize in studying the physical properties of speech are phoneticians. The field of phonetics is traditionally divided into three sub-disciplines based on the research questions involved such as how humans plan and execute movements to produce speech, how various movements affect the properties of the resulting sound, or how humans convert sound waves to linguistic information. Traditionally, the minimal linguistic unit of phonetics is the phone—a speech sound in a language which differs from the phonological unit of phoneme; the phoneme is an abstract categorization of phones, and it is also defined as the smallest unit that discerns meaning between sounds in any given language.
In articulatory phonetics, the place of articulation of a consonant is a location along the vocal tract where its production occurs. It is a point where a constriction is made between an active and a passive articulator. Active articulators are organs capable of voluntary movement which create the constriction, while passive articulators are so called because they are normally fixed and are the parts with which an active articulator makes contact. Along with the manner of articulation and phonation, the place of articulation gives the consonant its distinctive sound.
In phonetics, a plosive, also known as an occlusive or simply a stop, is a pulmonic consonant in which the vocal tract is blocked so that all airflow ceases.
In linguistics, voicelessness is the property of sounds being pronounced without the larynx vibrating. Phonologically, it is a type of phonation, which contrasts with other states of the larynx, but some object that the word phonation implies voicing and that voicelessness is the lack of phonation.
The human voice consists of sound made by a human being using the vocal tract, including talking, singing, laughing, crying, screaming, shouting, humming or yelling. The human voice frequency is specifically a part of human sound production in which the vocal folds are the primary sound source.
The larynx, commonly called the voice box, is an organ in the top of the neck involved in breathing, producing sound and protecting the trachea against food aspiration. The opening of larynx into pharynx known as the laryngeal inlet is about 4–5 centimeters in diameter. The larynx houses the vocal cords, and manipulates pitch and volume, which is essential for phonation. It is situated just below where the tract of the pharynx splits into the trachea and the esophagus. The word 'larynx' comes from the Ancient Greek word lárunx ʻlarynx, gullet, throat.ʼ
The field of articulatory phonetics is a subfield of phonetics that studies articulation and ways that humans produce speech. Articulatory phoneticians explain how humans produce speech sounds via the interaction of different physiological structures. Generally, articulatory phonetics is concerned with the transformation of aerodynamic energy into acoustic energy. Aerodynamic energy refers to the airflow through the vocal tract. Its potential form is air pressure; its kinetic form is the actual dynamic airflow. Acoustic energy is variation in the air pressure that can be represented as sound waves, which are then perceived by the human auditory system as sound.
Falsetto is the vocal register occupying the frequency range just above the modal voice register and overlapping with it by approximately one octave.
The voiceless glottal fricative, sometimes called voiceless glottal transition or the aspirate, is a type of sound used in some spoken languages that patterns like a fricative or approximant consonant phonologically, but often lacks the usual phonetic characteristics of a consonant. The symbol in the International Phonetic Alphabet that represents this sound is ⟨h⟩, and the equivalent X-SAMPA symbol is h. However, has been described as a voiceless vowel because in many languages, it lacks the place and manner of articulation of a prototypical consonant, as well as the height and backness of a prototypical vowel:
[h and ɦ] have been described as voiceless or breathy voiced counterparts of the vowels that follow them [but] the shape of the vocal tract [...] is often simply that of the surrounding sounds. [...] Accordingly, in such cases it is more appropriate to regard h and ɦ as segments that have only a laryngeal specification, and are unmarked for all other features. There are other languages [such as Hebrew and Arabic] which show a more definite displacement of the formant frequencies for h, suggesting it has a [glottal] constriction associated with its production.
In phonetics, the airstream mechanism is the method by which airflow is created in the vocal tract. Along with phonation and articulation, it is one of three main components of speech production. The airstream mechanism is mandatory for most sound production and constitutes the first part of this process, which is called initiation.
A vocal register is a range of tones in the human voice produced by a particular vibratory pattern of the vocal folds. These registers include modal voice, vocal fry, falsetto, and the whistle register. Registers originate in laryngeal function. They occur because the vocal folds are capable of producing several different vibratory patterns. Each of these vibratory patterns appears within a particular range of pitches and produces certain characteristic sounds.
The term stiff voice describes the pronunciation of consonants or vowels with a glottal opening narrower, and the vocal folds stiffer, than occurs in modal voice. Although there is no specific IPA diacritic for stiff voice, the voicing diacritic may be used in conjunction with the symbol for a voiced consonant. In Bru, for example, stiff-voiced vowels have tenseness in the glottis and pharynx without going so far as to be creaky voiced, whereas slack-voiced vowels are lax in the glottis without going so far as to be breathy voice.
Harsh voice, also called ventricular voice or pressed voice, is the production of speech sounds with a constricted laryngeal cavity, which generally involves epiglottal co-articulation. Harsh voice includes the use of the ventricular folds to damp the glottis in a way similar to what happens when a person talks while lifting a heavy load, or, if the sound is voiceless, like clearing one's throat. It contrasts with faucalized voice, which involves the expansion of the larynx.
Faucalized voice, also called hollow voice or yawny voice, is a vocal quality of speech production characterized by the vertical expansion of the pharyngeal cavity due to the lowering of the larynx. It is termed faucalized because of the stretching of the fauces and visible narrowing of the faucial pillars in the back of the oral cavity. During faucalized voice, the sides of pharynx expand outward and the larynx descends and tilts forward. The term "yawny voice" is appropriate to compare this voice quality to the physiological act of yawning. Its opposite is harsh voice, a vocal quality produced when the pharynx is contracted and the larynx raised. Faucalized voice is not to be confused with breathy voice, which involves relaxed vocal folds, greater velocity of airflow through the glottis and produces a lower pitch sound. Faucalized voice involves the forward tilting of the larynx which stretches the vocal folds and produces a higher pitch sound, despite the increased volume of the pharyngeal cavity.
Modal voice is the vocal register used most frequently in speech and singing in most languages. It is also the term used in linguistics for the most common phonation of vowels. The term "modal" refers to the resonant mode of vocal folds; that is, the optimal combination of airflow and glottal tension that yields maximum vibration.
Nasal clicks are click consonants pronounced with nasal airflow. All click types have nasal variants, and these are attested in four or five phonations: voiced, voiceless, aspirated, murmured, and—in the analysis of Miller (2011)—glottalized.
Voice Quality Symbols (VoQS) are a set of phonetic symbols used to transcribe disordered speech for what in speech pathology is known as "voice quality". This phrase is usually synonymous with phonation in phonetics, but in speech pathology encompasses secondary articulation as well.
Oral skills are speech enhancers that are used to produce clear sentences that are intelligible to an audience. Oral skills are used to enhance the clarity of speech for effective communication. Communication is the transmission of messages and the correct interpretation of information between people. The production speech is insisted by the respiration of air from the lungs that initiates the vibrations in the vocal cords. The cartilages in the larynx adjust the shape, position and tension of the vocal cords. Speech enhancers are used to improve the clarity and pronunciation of speech for correct interpretation of speech. The articulation of voice enhances the resonance of speech and enables people to speak intelligibly. Speaking at a moderate pace and using clear pronunciation improves the phonation of sounds. The term "phonation" means the process to produce intelligible sounds for the correct interpretation of speech. Speaking in a moderate tone enables the audience to process the information word for word.
1 2 3 4 5 Edmondson, Jerold A.; John H. Esling (2005). "The valves of the throat and their functioning in tone, vocal register, and stress: laryngoscopic case studies". Phonology. Cambridge University Press. 23 (2): 157–191. doi:10.1017/S095267570600087X. S2CID62531440.
↑ Large, John (February–March 1972). "Towards an Integrated Physiologic-Acoustic Theory of Vocal Registers". The NATS Bulletin. 28: 30–35.
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